In conveying systems employed in livestock barns, supply conveyors are typically used between the silo and the conveyor feed belts which run longitudinally of the barn and supply the feed alleys or bunk feeders. There may be one or more feed alleys or feed conveyors in a barn. If it is desired to discharge grain from the supply conveyor at a point intermediate the length of the conveyor, a drop out mechanism with doors is positioned at the appropriate location to discharge the feed into a feed alley or feed conveyor. Typically, the supply conveyor is located adjacent the ceiling of the barn and at an inconvenient location for easy access to the drop out doors. Accordingly, remote control is desirable to manipulate the doors at the desired time. Some of the supply conveyors in use have sliding doors. The present invention deals with mechanism for opening and closing hinged doors which, in the closed position, interfit in the side walls of the conveyor to close the door openings and, in the open position, permit feed to be discharged laterally and downwardly from the door openings. The present invention relates to a low profile door opening mechanism which enables close positioning of the top of the conveyor to the ceiling of a barn or other structure.